Diagnostic apparatus, such as endoscopes, are conventionally known and used for medical purposes. Typically, an elongated tubular or other shaped instrument body includes a insertion portion having viewing optics contained therein for allowing inspection of a subject of interest. In use, the insertion portion is directed through a surgical incision or other means into a body cavity, such as the colon, intestines, etc., allowing a disorder or other target of interest to be viewed. Nonmedical devices, such as borescopes, are used in a similar manner for inspection purposes, such as within enclosed pressure vessels, within aircraft or other structures limiting normal vision thereof.
Other known medical diagnostic devices include intraoral dental cameras which include a micro-video camera retained within the distal head of an elongated instrument body that is sized for insertion into the mouth of a patient. The micro-video camera includes a viewing lens portion which focuses an optical image onto a solid-state imager, such as a CMOS or CCD. An electrical signal is then relayed to processing circuitry which converts the signal into a monitor-ready video signal further relayed to a video monitor or other processing apparatus for providing real-time diagnostic analysis.
There is a specific and urgent need to provide a clean and sterile camera surface to the patient for prudent medical reasons. This need is heightened because there is typically bleeding in even the most routine of dental procedures, by which transmission of Hepatitis B, AIDS, etc, might occur if the instrument is not properly handled between patients. Because of the design of the instrument, it is preferable that the camera head, as well as the tubular instrument body, be properly cleaned due to the proximity to the mouth of the patient.
Sterilization is an option in which the instrument is dipped in a liquid bath containing a sterilization agent after use. Application of heat using an oven or other specialized apparatus is still another option. Each of such techniques, however, is time-consuming and may also affect the useful life of the instrument, which contains sensitive electronics and optics. Therefore, a protective flexible sheath, made from polyethylene or other suitable material such as those described in U.S. Pat. No. 4,757,381, has been developed which is sized to encase the tubular instrument body, including the distal camera head. The sheath includes a transparent viewing window to allow the lens portion of the camera to adequately view the subject area after the sheath has been attached.
In use, however, dentists or hygienists using the intraoral camera are required to grip the sheathed tubular instrument body in order to then inspect areas of a patient's mouth. Due to the loose fitting of the sheath to the instrument body, there are instances in which the sheath and/or the instrument is twisted, making support of the instrument difficult and invariably causing the viewing window of the sheath to be shifted from the field of view of the lens portion of the camera, producing unfavorable results.
The aforementioned '381 patent attempts to correct this problem in a number of ways, including heat shrinking a portion of the sheath to tighten the fit of the sheath onto the camera head. Alternative methods include applying a vacuum to the sheath or using fluid pressure to control the positioning of the sheath window in the vicinity of the camera lens. None of these methods are particularly convenient, nor do they aid in providing support for the user of the instrument.
U.S. Pat. No. 5,893,712 solves a number of the above-stated problems. Referring to FIG. 1, this reference describes the use of a hinged or two piece clam shell handle assembly which is fitted over the outer periphery of the instrument body and can be used to trap the sheath therebetween. Though this assembly is effective, it is costly to manufacture in relation to the cost of the instrument, which due to the advent of improved electronics and material manufacturing, can be made quite cheaply.
Therefore, there is a need to provide a gripping handle, such as for an intraoral dental camera or other diagnostic instrument, which is inexpensive to manufacture. There is a further need, particularly in the case of intraoral dental cameras, to provide an inexpensive gripping handle which allows a loosely fitted flexible protective sheath to be effectively supported to prevent twisting thereof and which is easy to attach and remove from the camera.